The author provides a portrait of the somewhat forgotten left wing, social democratic leader, Pal Justus. Justus who was sentenced to life imprison­ment by Rákosi, criticised the then policy of the Hungarian Communist Party from the left, from a basis of principles of consistent, Marxist principles. By presenting Justus's main ideas of principle, the author warns that social de­mocracy does not only contain the social democratic right, the revision of the Marxist concepts but – in a significant trend – also the consistent re­presentation of exactly these concepts. A topical message of Justus is that social democracy is not one single ideal: the bourgeois and the so­cialist ideas of democracy represent two rival concepts.